From 0789724f86a59fa7078d67dfeb1ee4a15ae3c693 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Thu, 26 Jul 2018 15:59:16 +0200 Subject: [PATCH] firmware: meson_sm: Add serial number sysfs entry The Amlogic Meson SoC Secure Monitor implements a call to retrieve an unique SoC ID starting from the GX Family and all new families. The serial number is simply exposed as a sysfs entry under the firmware sysfs directory. Signed-off-by: Neil Armstrong Signed-off-by: Kevin Hilman --- drivers/firmware/meson/meson_sm.c | 56 +++++++++++++++++++++++++++++++++ include/linux/firmware/meson/meson_sm.h | 1 + 2 files changed, 57 insertions(+) diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c index 0ec2ca87318c..29fbc818a573 100644 --- a/drivers/firmware/meson/meson_sm.c +++ b/drivers/firmware/meson/meson_sm.c @@ -24,6 +24,7 @@ #include #include #include + #include #include @@ -48,6 +49,7 @@ struct meson_sm_chip gxbb_chip = { CMD(SM_EFUSE_READ, 0x82000030), CMD(SM_EFUSE_WRITE, 0x82000031), CMD(SM_EFUSE_USER_MAX, 0x82000033), + CMD(SM_GET_CHIP_ID, 0x82000044), { /* sentinel */ }, }, }; @@ -214,6 +216,57 @@ int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index, } EXPORT_SYMBOL(meson_sm_call_write); +#define SM_CHIP_ID_LENGTH 119 +#define SM_CHIP_ID_OFFSET 4 +#define SM_CHIP_ID_SIZE 12 + +static ssize_t serial_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + uint8_t *id_buf; + int ret; + + id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL); + if (!id_buf) + return -ENOMEM; + + ret = meson_sm_call_read(id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID, + 0, 0, 0, 0, 0); + if (ret < 0) { + kfree(id_buf); + return ret; + } + + ret = sprintf(buf, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n", + id_buf[SM_CHIP_ID_OFFSET + 0], + id_buf[SM_CHIP_ID_OFFSET + 1], + id_buf[SM_CHIP_ID_OFFSET + 2], + id_buf[SM_CHIP_ID_OFFSET + 3], + id_buf[SM_CHIP_ID_OFFSET + 4], + id_buf[SM_CHIP_ID_OFFSET + 5], + id_buf[SM_CHIP_ID_OFFSET + 6], + id_buf[SM_CHIP_ID_OFFSET + 7], + id_buf[SM_CHIP_ID_OFFSET + 8], + id_buf[SM_CHIP_ID_OFFSET + 9], + id_buf[SM_CHIP_ID_OFFSET + 10], + id_buf[SM_CHIP_ID_OFFSET + 11]); + + kfree(id_buf); + + return ret; +} + +static DEVICE_ATTR_RO(serial); + +static struct attribute *meson_sm_sysfs_attributes[] = { + &dev_attr_serial.attr, + NULL, +}; + +static const struct attribute_group meson_sm_sysfs_attr_group = { + .attrs = meson_sm_sysfs_attributes, +}; + static const struct of_device_id meson_sm_ids[] = { { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip }, { /* sentinel */ }, @@ -242,6 +295,9 @@ static int __init meson_sm_probe(struct platform_device *pdev) fw.chip = chip; pr_info("secure-monitor enabled\n"); + if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group)) + goto out_in_base; + return 0; out_in_base: diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h index 37a5eaea69dd..f98c20dd266e 100644 --- a/include/linux/firmware/meson/meson_sm.h +++ b/include/linux/firmware/meson/meson_sm.h @@ -17,6 +17,7 @@ enum { SM_EFUSE_READ, SM_EFUSE_WRITE, SM_EFUSE_USER_MAX, + SM_GET_CHIP_ID, }; struct meson_sm_firmware; -- 2.11.0